Fast Food Fattiest in U.S., Study Finds

You may get more trans fat in chicken nuggets and french fries bought at McDonald’s and KFC restaurants in New York City than in France, London, or Russia, doctors report in The New England Journal of Medicine.

In a letter to the journal, Steen Stender, MD, and colleagues show that trans fat levels vary worldwide -- and sometimes within the same country -- for McDonald’s and KFC chicken nuggets and french fries.

Stender works at Gentofte University Hospital in Hellerup, Denmark. While traveling for other reasons between November 2004 and September 2005, Stender and colleagues ordered a large serving of french fries (171 grams) and chicken nuggets (160 grams) at McDonald’s or KFC restaurants in 43 U.S. and international locations.

The researchers analyzed the foods’ total fat and trans fat content.

Tracking Trans Fat

Trans fat, or trans fatty acids (TFA), are fats found in foods such as vegetable shortening, some margarines, and many processed foods made with or fried in partially hydrogenated oils.

Trans fat, like saturated fat and dietary cholesterol, raises the LDL (or "bad") cholesterol that increases your risk for heart disease, according to the FDA.

“It is recommended that the consumption of trans fat be as low as possible,” write Stender and colleagues.

Stender’s team writes that “the content of trans fatty acids varied from less than 1 gram in Denmark and Germany, to 10 grams in New York (McDonald’s) and 24 grams in Hungary (KFC).”

Those numbers combine trans fat content for the chicken nuggets and french fries.

Trans Fat Levels Varied

For the McDonald’s items, the top three locations for trans fat content were New York, Peru, and Atlanta. The results for McDonald’s restaurants didn’t include other U.S. cities.

For the KFC foods, the top three locations for trans fat content were Hungary, Poland, and Peru, the study shows. The only U.S. location on the list -- New York -- ranked eighth.

“The cooking oil used for French fries in McDonald’s outlets in the United States and Peru contained 23 percent and 24 percent trans fatty acids, respectively, whereas the oils used for French fries in many European countries contained only about 10 percent trans fatty acids, with some countries as low as 5 percent (Spain) and 1 percent (Denmark),” the researchers write.

What about french fries in France? Trans fat content was in the middle of the range (15 percent for McDonald’s fries and 8 percent for KFC fries).

The study doesn’t cover every restaurant in every location. The findings may not apply in other cities or restaurants. The study didn’t do a head-to-head comparison of McDonald’s and KFC foods.

McDonald’s Replies

WebMD called the media relations offices of McDonald’s Corporation and KFC for their comments.

"McDonald's takes the matter of trans fatty acids seriously,” the statement reads. “In fact, it is important to note that this Letter to the Editor itself draws heavily from information provided by McDonald's web site -- a clear example of our commitment to transparency on this issue.”

One of the five footnotes in the researchers’ letter to the journal cites McDonald’s nutritional information.

"McDonald's continues to work diligently on ways to reduce TFA levels in our fries,” McDonald’s statement continues. “Our reduction in the U.S. is taking longer than anticipated, as we have previously announced. However, we continue to progress in our testing and we are determined to get it right for our customers."

KFC sent an email to WebMD stating that "our product offerings vary from country to country to reflect local taste preferences, and we do make nutritional information available to our customers."